JP7157803B2 - conditioning shampoo composition - Google Patents

Description

The present invention relates to conditioning shampoos or cleansing compositions. More specifically, the present invention relates to shampoos or cleansing compositions containing naturally occurring sulfonated methyl esters (SMEs) and having improved conditioning benefits. This shampoo composition is suitable for use in cleansing and conditioning the hair and skin, especially the hair and scalp.

In the industry, hair care and skin care product formulations commonly contain small oil drops that condition the hair and skin. Shampoos, cleansing compositions, body washes, and other personal care products also contain anionic surfactants, which adsorb and negatively affect substrates and oil droplets such as hair and scalp. Provides surface charge. The resulting electrostatic repulsion suppresses oil droplet deposition on the substrate.

To overcome this undesirable effect, each formulation of personal care compositions, such as shampoos and cleansing compositions, also includes cationic polymers that act as mediators to adhere the droplets to the substrate. In the bulk of solution, surfactants and polymers form joint aggregates, also known as "coacervates." Therefore, both surfactants and polymers can adsorb to the surface of oil droplets and solid substrates. They are also present in the wetting films interposed between the oil droplets and the substrate. The interactions of surfactants and polymers in the bulk and in the thin liquid films are of paramount importance to the oil droplet deposition process. At higher concentrations, surfactants in personal care formulations hydrophilize cationic polymers and oil droplets. When the personal care formulation is rinsed off the substrate, most surfactants are washed away, except for the relatively hydrophobic polymer molecules that adsorb the oil droplets while mediating their adhesion to the substrate. As a result, it is believed that when the surfactant in the personal care composition is diluted to some extent, oil bead deposition or adhesion occurs.

There is a great deal of work in this technical area related to determining the amount of deposited oil by spectroscopy. These methods reveal the total amount of oil as the final result of the deposition process. However, they do not provide information about the occurrence of the oil droplet deposition process, particularly the degree of dilution at which oil droplet deposition begins. Oil deposition determines the deposition or deposition of oil droplets on substrates such as the hair and scalp, as well as the active ingredients carried therein, and thus influences the conditioning effect of personal care compositions on substrates. . However, in view of their associated conditioning effects on substrates, the oil deposition effects of different surfactants used in personal care compositions such as shampoos and cleansing compositions have not been investigated in the industry so far.

Various types of conditioning shampoos and cleansing compositions exist in the art that utilize sodium lauryl ether sulfate (SLES) as the primary surfactant. For example, hair conditioning shampoos containing 5% to 50% anionic surfactants such as SLES are disclosed in International Publication No. WO9308787A2. The hair conditioning shampoo can optionally include a cationic polymer and a zwitterionic surfactant such as betaine in its formulation. This publication also discloses the use of a mixture of silicone oil as a conditioning agent, with silicone resin added to enhance the deposition efficiency of the composition. However, this publication does not disclose the use of specific types of anionic surfactants to enhance oil droplet deposition. The oil droplet deposition ability of SLES is also not investigated in any of the prior art.

SMEs, also called α-sulfo fatty acid methyl esters or methyl ester sulfonates (MES), are used in many products including personal cleansing solutions, shampoo compositions, laundry detergents and dishwashing detergents. is a class of anionic surfactants increasingly used as cleaning and wetting agents in industrial and household applications. SMEs (SMEs) derived from natural renewable resources such as palm oil are known to be biodegradable and renewable and are considered as environmentally friendly alternative surfactants. However, SMEs (SMEs) are not commonly used in the industry as primary surfactants in hair and scalp shampoos and cleansing compositions.

European Patent No. EP 0796084 A2 discloses a skin cleansing liquid containing a lathering synthetic surfactant. The lathering synthetic surfactant can be an anionic surfactant such as acyl isethionates, acyl sarcosinates, alkylglycerylether sulfonates, acyl lactylate. can. This publication discloses that the cleansing liquid has a specific Lipid Deposition Value (LDV) of 5-1000 μg of lipid per square centimeter of skin. This publication also discloses that the composition requires a stabilizer such as crystalline ethylene glycol fatty acid ester to increase fluid deposition on the skin. . SMEs are only disclosed as one of a number of anionic surfactants that can be used in skin cleansing liquids. However, this publication does not disclose the use of specific SME compounds or specific mixtures of SMEs in formulations suitable for hair and scalp conditioning. The specific oil droplet deposition effect of surfactants is also not disclosed in this publication.

The prior art of conditioning shampoos and cleansing compositions containing certain SME compounds does not disclose any relationship between conditioning benefits and oil bead deposition in the presence of different types of surfactants. Therefore, shampoos and cleansing compositions with improved conditioning effects from new technical aspects are desired.

One of the objects of the present invention is to provide a shampoo or cleansing composition for use in cleansing and conditioning the hair and scalp, whereby oil droplets are deposited on the substrate (i.e. hair and scalp). can be enhanced, thereby improving conditioning benefits.

The present invention also aims to provide shampoos or cleansing compositions containing natural and environmentally friendly anionic surfactants such as SMEs, which also exhibit improved robustness of oil droplet deposition on substrates. A wide range of oil droplet deposition values (C _adh ) is achieved in order to create a more effective conditioning composition that can be applied.

At least one of the proceeding objects is wholly or partly fulfilled by the present invention, and one embodiment of the present invention has chain lengths of 12-20 carbon atoms (C12-C20). A shampoo composition for enhancing the deposition of oil droplets on a substrate comprising a mixture of SME compounds comprising two or more fatty acid SMEs (SMEs) with Describe things.

According to one embodiment of the invention, the mixture of SME compounds is a mixture between C12 SME and C18 SME, a mixture between C14 SME and C16 SME, a mixture between C14 SME and C18 SME, or It is a mixture between C16 SME and C18 SME.

According to another embodiment of the invention, the mixture of SME compounds comprises 55%-95% C16 SME and 5%-45% C18 SME.

In certain embodiments, the composition further comprises an inorganic electrolyte as an oil droplet deposition enhancer. Preferably, the inorganic electrolyte can be sodium chloride (NaCl) or potassium chloride (KCl).

One embodiment of the present invention discloses that the zwitterionic surfactant is an alkylbetaine. Preferably, the zwitterionic surfactant is cocamidopropyl betaine (CAPB). While another embodiment of the present invention discloses that the cationic polymer is guar gum.

According to one preferred embodiment of the invention, the mixture of SME compounds and the zwitterionic surfactant are present in a combined ratio of 5-7.5:1 by weight. Preferably, the mixture of SME compounds and zwitterionic surfactant are present in a total weight of 6% to 20% by weight of the composition.

In one embodiment, it is also disclosed that the oil phase comprises silicon oil, mineral oil, vegetable oil, animal oil or an oil-in-water emulsion thereof.

The use of a shampoo composition for enhancing the deposition of oil droplets on a substrate is also disclosed in one further embodiment of the invention, the composition comprising chains of 12-20 carbon atoms (C12-C20). A mixture of SME compounds comprising two or more long fatty acid SMEs (SMEs), a zwitterionic surfactant, an oil phase, and a cationic polymer. Preferably, the composition comprises a specific mixture of SME compounds.

Preferred embodiments of the present invention consist of the novel combination of features and arrangements hereinafter more fully described or illustrated in the accompanying drawings and, in particular, as defined in the appended claims. It will be appreciated that various changes in detail may be effected by those skilled in the art without departing from the scope or sacrificing the advantages of the invention.

To facilitate the understanding of the invention, the accompanying drawings illustrate preferred embodiments from research when considered in connection with the following description, the invention, its construction and operation, and its advantages. are easily understood and appreciated.
1(a)-(d) show successive stages of detachment of an initially compressed oil droplet in the presence of droplet/substrate attachment, according to one embodiment of the present invention. Figures 2(a)-(d) show successive stages of detachment of an initially compressed oil droplet in the absence of droplet/substrate attachment, according to one embodiment of the present invention. Figures 3(a) and (b) show deposition concentration _Cadh versus CAPB in a mixture comprising three different anionic surfactants: SLES-1EO, C14 SME and C16 SME, according to one embodiment of the present invention. Fig. 10 is a graph showing mole fraction X _CAPB ; Here, (a) is a hydrophobic glass substrate and (b) is a hydrophilic glass substrate. The lines are for making the graph easier to see. FIG. 4 shows a solution of C16-SME and Jaguar®-C-13-S (left), or SLES-1EO and Jaguar, after soaking in silicone oil containing the fluorescent dye Bodipy. Figure 2 shows a reflected light micrograph of human hair soaked in a solution of (Jaguar®)-C-13-S (right). The threshold adhesion concentrations are found to be 1 wt% and 0.25 wt% for C16-SME and SLES-1EO, respectively. Different hairs of the same origin are used in different concentrations. FIG. 5 is a graph showing deposition concentration _Cadh versus concentration of cationic polymer (Jaguar®-C-13-S), in which the concentration of SME compound A mixture (C16-C18 SME) is used as the primary surfactant.

The present invention will now be described according to preferred embodiments of the present invention with reference to the accompanying description and drawings. However, limiting the description to the preferred embodiment of the invention and the drawings is merely to facilitate discussion of the invention, and one of ordinary skill in the art may make various modifications without departing from the scope of the appended claims. It is assumed that modifications can be considered.

The present invention discloses personal care compositions, i.e. shampoos or cleansing compositions, for enhancing the deposition of oil droplets on substrates such as hair and scalp. Shampoo compositions contain a mixture of SME compounds as the primary surfactant. The mixture of SME compounds includes two or more long-chain SMEs (SMEs), eg, fatty acid SMEs (SMEs) having a chain length of 12-20 carbon atoms (C12-C20). As a conditioning shampoo, the composition also contains a zwitterionic surfactant, an oil phase and a cationic polymer.

According to one embodiment of the invention, the mixture of SME compounds is a mixture between C12 SME and C18 SME, a mixture between C14 SME and C16 SME, a mixture between C14 SME and C18 SME, or It can be a mixture between C16 SME and C18 SME. For example, the mixture of SME compounds is a mixture of C16 SME and C18 SME comprising 55% to 95% C16 SME and 5% to 45% C18 SME by weight of the SME compound. In another example, the mixture of SME compounds is a mixture of 60%-90% C16 SME and 10%-40% C18 SME, or 65%-85% C16 SME and 15%-35% C18 SME. It can be a mixture. Alternatively, the mixture of SME compounds can be a mixture of 90%-95% C16 SME and 5%-10% C18 SME.

In general, C16 and C18 SMEs can be derived from natural sources such as vegetable oils, including palm oil, and animal fats and oils. Specifically, C16 SME can be obtained from palmitic acid. On the other hand, C18 SME can be obtained from palm oil stearic acid. Both of these SMEs were obtained by sulfonation of methyl ester. C16 SME and C18 SME have molecular structures as shown in formulas (I) and (II) below, respectively.

In one embodiment of the invention it is disclosed that the zwitterionic surfactant is an alkyl betaine, or betaines, especially CAPB. Preferably, the total amount of mixture of surfactants (ie mixture of SME compound and zwitterionic surfactant) is present in an amount of 6% to 20% by weight of the composition. For example, the total amount of mixture of SME compounds (eg mixture of C16 and C18 SMEs) and CAPB can be present in an amount of 10% to 15% by weight of the composition. More specifically, the total amount of surfactant mixture can be present at about 12% to 13% by weight of the shampoo composition. It should be understood in the art that zwitterionic surfactants can also be described as amphoteric surfactants under certain conditions.

According to one preferred embodiment of the present invention, the mixture of SME compounds and the zwitterionic surfactant such as CAPB should be present in a specific combination ratio, ie 5-7.5:1 by weight. A lower CAPB content results in a more oily composition but less lathering of the shampoo. Conversely, a higher content of CAPB results in better lathering but reduces oil droplet deposition of the composition. Therefore, for optimum conditioning performance, a mixture of SME compounds and CAPB was combined to produce a shampoo composition with comparable lathering and detergency to cleansing action while avoiding suppression of oil bead deposition effects. It is important that the combination ratio is properly adjusted.

As disclosed in other embodiments of the invention, the shampoo composition comprises a cationic polymer which may be guar gum. More specifically, the guar gum can be guar hydroxypropyltrimonium chloride. It is a trade name for Jaguar® such as Jaguar® C-13-S, Jaguar® C-14-S, Jaguar® )) commercially available as C-17, Jaguar® Excel, or other cationic polymers of similar chemical composition. Polymers are larger and relatively more hydrophobic than surfactants so that they can irreversibly adsorb to the oil droplets in the shampoo composition and are not washed away like surfactants during the rinsing process of the shampoo composition. should be sexual. The concentration of the cationic polymer can be adjusted appropriately by those skilled in the art for use in shampoo compositions. It can also be adjusted based on the total surfactant concentration of the shampoo composition.

Without being bound by theory, it is believed that oil droplet deposition of the composition is governed by electrostatic forces, hydrophobicity, and polymer-bridging surface forces. Anionic surfactants (ie, SME compounds) and cationic polymers (eg, guar hydroxypropyltrimonium chloride) adsorb to the surface of oil droplets. SME-based surfactants hydrophilize the cationic polymer and oil droplets during high concentrations of the shampoo composition so that when the shampoo composition is applied to a substrate for cleansing or washing, the oil is No droplet deposition is observed. When diluted (washing out the shampoo composition) most of the SMEs (SMEs) are washed away while the cationic polymer is still adsorbed on the oil droplets. Such adsorption mediates the adsorption of the oil droplets and the active ingredients and nutrients contained therein to the substrate, ie, to the hair and scalp.

SME compounds play an important role in stabilizing dispersed oil droplets and polymer aggregates in formulations. At low surfactant concentrations, it is believed that polymer bridging occurs, resulting in oil flocculation. As a result, most of the surfactant is washed away during rinsing, but some of it is still adsorbed on the oil droplets and can affect adherence to the substrate.

In certain embodiments, shampoo compositions may include inorganic electrolytes. For example, the inorganic electrolyte can be NaCl, KCl, or another electrolyte that does not cause precipitation in the formulation. Addition of inorganic electrolytes such as NaCl to concentrated mixed micellar solutions of anionic surfactants and CAPB can increase viscosity. Thus, NaCl can be used as a thickening agent in shampoo compositions.

In the present invention, NaCl can be added to the shampoo compositions of the present invention as an oil deposition enhancer. Experimental data show that SME-containing shampoo compositions, especially when NaCl is added, induce a strong oil deposition effect with oil deposition values (C _adh ) ranging from 0.01% wt to 1.00% wt. can be done. Even without the addition of NaCl, SME-based shampoo compositions exhibited superior or enhanced oil deposition effects and higher _Cadh values than shampoo compositions containing other types of primary surfactants, such as SLES. give. Without being bound by theory, it is believed that the increased oil droplet deposition in the presence of NaCl is due to salting-out effects and screening of the electrostatic double-layer repulsion of hydrocarbon chains in water. It is thought to be caused by the reinforcing effect of salt on the inter-segment attraction of . Additionally, other inorganic electrolytes that can suppress electrostatic repulsion between the droplet and substrate can also produce effects similar to NaCl.

As disclosed in another embodiment of the present invention, the oil phase of the shampoo composition is silicone oil, mineral oil, vegetable oil, animal oil, or silicone oil, mineral oil, vegetable oil, or animal oil. including those oil-in-water emulsions such as oil-in-water emulsions containing The oils used should not be solubilized in the surfactant micelles of hydrocarbon chain surfactants present in the shampoo composition and are washed out with the surfactant solution during rinsing. shouldn't. Additionally, the oils used should not be readily oxidized. Preferably, silicone oils are used in shampoo compositions.

In certain embodiments, shampoo compositions may include active ingredients that benefit the hair and scalp. Such active ingredients are solubilized and carried by oil droplets, surfactants and other carriers. Active ingredients can be nutritional ingredients such as vitamins and minerals, naturally occurring plant oils including essential oils, bioflavonoids, and antioxidants. For example, vitamins and minerals can be vitamin E (tocotrienols, tocopherols or combinations thereof), vitamin A, silica, magnesium, calcium, potassium, zinc, copper, selenium, chromium and sulfur. Naturally derived vegetable oils include argon oil, mint leaf oil, marula oil, olive oil, tea tree oil, coconut sheer oil, rapeseed oil. It can be oil or the like.

In certain embodiments, the shampoo composition contains additives that provide specific hair care benefits, such as hair moisturizing or hydrating agents, oil control agents, hair loss control agents, hair darkening agents, anti-frizz agents. anti-frizz agents, hair relaxing agents, nourishing agents, or hair color protecting agents. Additionally, the shampoo composition may also contain preservatives, stabilizers, fragrances, colorants, or a combination of any two or more thereof.

According to a further embodiment of the invention, the composition is free of non-ionic surfactants such as coco-fatty-acid-monoethanolamide (CMEA). CMEA is also known to be a viscosity modifier for concentrated mixed micellar solutions of anionic surfactants and CAPB, but the addition of CMEA to shampoo compositions inhibits oil droplet deposition on the substrate of the composition. can. Without wishing to be bound by theory, nonionic surfactants such as CMEA bind to the hydrocarbon chains making them more hydrophilic, and within the surfactant system of the shampoo composition, the intersegmental hydrophobic It is thought to suppress the effects of sexual attraction and polymer cross-linking.

The use of a shampoo composition for enhancing oil droplet deposition on substrates is also disclosed in one further embodiment of the present invention, wherein the composition contains 14-20 carbon atoms (C14-C20). It includes mixtures of SME compounds containing two or more chain-length fatty acid SMEs (SMEs), zwitterionic surfactants, and cationic polymers. Preferably, the composition comprises a specific mixture of SME compounds. For example, a particular mixture of SME compounds is a mixture of 55% to 95% C16 SME and 5% to 45% C18 SME by weight of SME compound.

As mentioned in the discussion above, the Pressed Drop Method (PDM) can be used to investigate oil droplet adhesion to solid substrates. This method provides information on the occurrence and mechanism of the oil droplet deposition process. An exemplary method of PDM is further detailed in Example 1. Based on this experimental data, the oil droplet deposition effect exhibited by different types of surfactants varies. In particular, the data show higher _Cadh in the presence of C14-SME and C16-SME and lower _Cadh in the presence of SLES, which in SME-based compositions is more easily enhanced. The carbon chain length of the SME can also affect the oil deposition efficiency of the shampoo. Therefore, it is preferred to use mixtures of specific SME compounds, for example mixtures of C16 and C18 SMEs (SMEs) are used in the shampoo compositions of the present invention.

As the shampoo composition is rinsed off the substrate, the surfactant concentration and oil droplet concentration decrease in the same proportion. When oil droplet deposition is proportional to oil droplet concentration, as derived from experimental data, the C _adh value of the composition increases approximately 3-4 times (300%-400%) when SLES is replaced with C16-SME. ) will increase.

Based on the different substrates, namely hydrophobic and hydrophilic substrates used in the experiments, we conclude that the adhesion of oil droplets on hydrophobic glass is easier compared to hydrophilic glass, as expected. be able to. However, by using SME-based surfactants in the composition, oil droplet deposition can be achieved on both types of substrates.

As mentioned in the preceding description, the oil droplets of the shampoo composition can contain different types of oil. Experimental results using silicone oil and oil droplets from vegetable oils such as sunflower seed oil yielded the same results for oil droplet deposition effects, as shown by their _Cadh versus X _CAPB experimental curves. is generated. This is because the oil droplets, regardless of their origin, are covered with a dense adsorption layer of both surfactant and polymer, and the substrate interacts with the adsorption layer rather than the oil phase itself. is. In other words, the adhesion of the droplet to the substrate is governed by the attractive forces in the aqueous film (surfactant and polymer stabilizing) interposed between the droplet and the substrate. After evaporation of water, direct contact between oil and substrate occurs. Based on experimental data, _Cadh has been shown to be non-sensitive and unaffected by various types of oils.

Comparative experiments can also study the difference between using separate oil-in-water emulsions of silicon oil droplets and silicon oil. Exemplary experimental results show that oil-in-water emulsions can also produce comparable _Cadh values, similar to those obtained with individual silicone oil droplets.

At higher surfactant concentrations, shampoo compositions exhibit a cleansing action. That is, as a cleansing composition for substrates such as hair and scalp, it removes (exfoliates) oil droplets deposited on the substrate. As characterized by enhanced values of _Cadh , oil beading of SME-based shampoo compositions occurs after some dilution and at lower surfactant concentrations, providing conditioning benefits to the hair and scalp. . The enhanced oil droplet deposition effect can be further demonstrated in comparative experiments using human hair as substrate, demonstrating the utility of SME (instead of SLES) for enhancing oil droplet deposition on hair from shampoo formulations. can be proved. A comparative utility study is further detailed in Example 3, demonstrating the efficacy of shampoo formulations containing Jaguar C-13-S and C16-SME or SLES-1EO on human hair.

Example 4 presents an experiment to determine the optimum cationic polymer concentration for oil droplet deposition, in which a mixture of SME compounds (C16-C18 SME) is applied as the primary surfactant. The concentration of cationic polymer can be adjusted according to the desired properties of the shampoo composition.

Example 1 Types of Surfactants Used in Pressed Drop Method (PDM) Various Several surfactants were tested, including anionic surfactants (C14-SME, C16-SME and SLES), anionic/zwitterionic surfactant mixtures, other surfactants and salt additives.

The myristic and palmitic (C14 and C16) SMEs (SMEs) used in the experiments were obtained from the Malaysian Palm Oil Board (MPOB) and KLK OLEO. C14-SME (Mw=344 g/mol) and C16-SME (Mw=372 g/mol) were supplied as dry powders. The critical micelle concentrations (CMC) of C14- and C16-SMEs obtained by electric conductivity measurements are 4.0 and 1.1 mM, respectively. On the other hand, the SLES used had one ethylene oxide group and a molecular weight of 332.4 g/mol. It is commercially available from Stepan Co. under the name STEOL CS-170. The critical micelle concentration of STEOL CS-170 is 0.7 mM as determined by both conductivity and surface tension measurements at 25°C. STEOL CS-170 contains alkyl chains ranging from C10-16.

The zwitterionic surfactant used was CAPB, a product of Evonik under the trade name Tego(R) Betain F50. The molecular weight is 356 g/mol. The CMC of CAPB was 0.09 mM, determined by surface tension measurements at 25°C. The cationic polymer was Jaguar® C-13-S, a high molecular weight polymer product from Solvay. The ionic strength was changed by the addition of NaCl, commercially available from Sigma, Germany. Aqueous solutions were prepared in deionized water. All experiments were performed at a temperature of 25°C. The silicone oil used was a vinyl-terminated polydimethylsiloxane (Gelest Inc.) with a kinematic viscosity of 100 cSt and a mass density of 0.97 g/cm ³ . Sunflower seed oil (SSO) was also used as a comparison.

The substrates used in the experiments included hydrophilic microscope slides (glass plates) and hydrophilic microscope slides, which were hydrophobized (silanized) with hexamethyldisilazane (HMDS). included.

Example 2 Pressed drop method (PDM)
The PDM experiment was set up based on an experimental model modified from the capillary meniscus dynamometry method, as described in prior art Danov, et al., 2016. In the experiment, oil droplets were formed at the tip of a metal capillary (hollow needle) with an outer diameter of 1.83 mm. The metal capillary was attached to a DSA30 instrument (Kruss GmbH, Germany) upgraded with a piezo-driven membrane to precisely control the droplet volume. Increasing volumes forced the droplets onto the substrate, which was placed at the bottom of a glass cuvette filled with the aqueous solution to be tested. Various degrees of dilution of the initial solution were achieved by replacing part of the solution with pure water while keeping the amount of aqueous phase in the cuvette constant.

First, the cuvette was filled with a concentrated solution of surfactant or surfactant and polymer. The initial total concentration of SLES and CAPB applied was 6% by weight and the initial polymer concentration was 0.1% by weight of Jaguar® C-13-S. Oil droplets were formed at the tip of the capillary in the solution of polymer and surfactant. The droplet was first pressed onto the substrate and kept in contact with the substrate for 10 minutes before being pulled away from it. During detachment, the droplet profile (ie, the change in oil droplet shape) indicates whether there was (or was not) droplet attachment to the substrate. Figures 1 and 2 show successive stages of detachment of an initially compressed oil droplet with and without droplet/substrate attachment, respectively. Oil droplets can be pushed away from the substrate several times to ensure the reproducibility of the experimental results.

Experiments were repeated with varying degrees of dilution. This allows determination of the threshold concentration _Cadh for droplet deposition. The initial surfactant concentration was relatively high (6 wt%) and was reduced stepwise. At each step, the droplet was detached to check if the droplet was attached. At higher surfactant concentrations the droplets did not adhere, but at lower ones they did. The initial (highest) surfactant concentration at which signs of droplet adhesion (FIG. 1) were observed was taken to be the threshold concentration for droplet adhesion _Cadh .

To characterize the degree of hydrophilicity/hydrophobicity of the substrate (glass plate), a drop of pure water is placed on its surface and the three-phase contact angle ( three-phase contact angle) was measured. The average contact angle measured using many plates is 23.1 degrees ± 5 degrees for hydrophilic (untreated) glass plates and 87.7 degrees ± 5 degrees for hydrophobized glass plates. For comparison, the advancing contact angle of hair is between 103 degrees (virgin hair) and 70 degrees (chemically damaged hair). That is, the contact angle of the hydrophobized plate lies in the middle of this range of angles.

In these experiments, the zwitterionic surfactant was CAPB used in mixed solution with one of the anionic surfactants C14-SME, C16-SME and SLES. The total initial surfactant concentration was fixed at 6% by weight. On the other hand, the weight fraction of CAPB in the surfactant mixture was X _CAPB = w _CAPB /(w _CAPB +w _anionic ). where w _CAPB and w _anionic are the weight concentrations of CAPB and anionic surfactant, respectively. All solutions contained the same initial concentration of 0.1 wt% Jaguar® C-13-S.

FIG. 3(a) shows a plot of C _adh versus X _CAPB for silicon oil and hydrophobized glass substrates for three anionic surfactants, C14-SME, C16-SME and SLES. In all cases, the highest C _adh (easiest oil droplet deposition) was observed with 100% anionic surfactant (X _CAPB =0), whereas with 100% CAPB (X _CAPB =1), C _adh was the lowest. _Cadh decreases monotonically with increasing _XCAPB . Furthermore, in the presence of C16-SME, _Cadh is highest (easiest for oil droplet deposition) and lowest in the presence of SLES, with C14-SME having intermediate _Cadh values.

For hydrophilic glass substrates, shown in Fig. 3(b), the behavior of the _Cadh vs. X _CAPB -dependent relationship is similar to that for hydrophobized glass, as shown in Fig. 3(a), with only _Cadh values is about two times lower. In other words, oil droplet adhesion on hydrophilic glass is more difficult than on hydrophobic glass (θ=23.1), as expected.

The interfacial tension of the two oils to the solution of surfactant and polymer is not identical. For example, for 6 wt% 3:1 C14-SME:CAPB + 0.1 wt% Jaguar® C-13-S, the interfacial tension is 3.50 and 2.25 mN/m. Nevertheless, experiments with droplets from silicone oil and SSO gave the same results as the _Cadh versus X _CAPB experimental curves.

Example 3 Comparative Experiments Using Human Hair as Substrate Comparative experiments were performed using human hair (as substrate) and shampoo formulations containing Jaguar C-13-S and C16-SME or SLES-1EO. was broken All other conditions were the same as described in the PDM method of Example 2. Silicone oil contains the fluorescent marker (dye) Bodipy (difluoro{2-[1-(3,5-dimethyl-2H-pyrrol-2-ylidene-N)ethyl]-3,5-dimethyl-1H-pyrrolato-N }boron) Sigma, CAS: 121207-31-6. The hair was first soaked in silicone oil and then in solutions of surfactants and polymers at varying degrees of dilution.

As shown in Figure 4, at higher concentrations no oil droplets remained deposited on the hair, while at lower concentrations many deposited oil droplets were observed. The threshold concentration for droplet deposition is about 4-fold higher for C16-SME compared to SLES-1EO. The threshold deposition concentrations are about 1 wt% and about 0.25 wt% for C16-SME and SLES-1EO, respectively.

Example 4 Optimal Jaguar C-13-S Concentration for Oil Droplet Deposition PDM experiments showed that the threshold deposition concentration C _adh measured as a function. The resulting dependence (shown in Figure 5) shows a clear maximum at 0.075 wt% Jaguar C-13-S. This represents the optimum concentration of this cationic polymer for oil droplet deposition at a total surfactant concentration of 6 wt% (1:1 C16-C18-SME:CAPB). This experiment demonstrates (i) the existence of an optimal ratio of polymer to surfactant, and (ii) that PDM is an appropriate method for determining this optimal ratio.

Claims (18)

a mixture of sulfonated methyl ester compounds comprising two or more sulfonated methyl esters of fatty acids having a chain length of 12 to 20 carbon atoms (C12-C20);
a zwitterionic surfactant;
an oil phase;
a cationic polymer;
including
said mixture of sulfonated methyl ester compounds and said zwitterionic surfactant are present in a total weight of 10% to 15% by weight of the composition;
said mixture of sulfonated methyl ester compounds and said zwitterionic surfactant are present in a combined ratio of 5 to 7.5:1 by weight;
A shampoo composition for enhancing the deposition of oil droplets on a substrate. said mixture of sulfonated methyl ester compounds is a mixture between C14 sulfonated methyl ester and C16 sulfonated methyl ester, a mixture between C14 sulfonated methyl ester and C18 sulfonated methyl ester, or C16 sulfonated methyl ester and a C18 sulfonated methyl ester. The composition of claim 1, wherein said mixture of sulfonated methyl ester compounds comprises 55% to 95% C16 sulfonated methyl ester and 5% to 45% C18 sulfonated methyl ester. The composition of any one of claims 1-3, wherein the composition further comprises an inorganic electrolyte. 5. The composition of claim 4, wherein said inorganic electrolyte is sodium chloride or potassium chloride. A composition according to any preceding claim, wherein said zwitterionic surfactant is an alkylbetaine. 7. The composition of Claim 6, wherein said alkyl betaine is cocamidopropyl betaine. A composition according to any preceding claim, wherein the cationic polymer is guar gum. A composition according to any one of claims 1 to 8 , wherein the oil phase is silicon oil, mineral oil, vegetable oil, or an oil-in-water emulsion thereof. Use of a shampoo composition for enhancing adhesion of oil droplets to a substrate, comprising:
the composition comprising:
a mixture of sulfonated methyl ester compounds comprising two or more sulfonated methyl esters of fatty acids having a chain length of 12 to 20 carbon atoms (C 12 -C20);
a zwitterionic surfactant;
an oil phase;
a cationic polymer;
including
said mixture of sulfonated methyl ester compounds and said zwitterionic surfactant are present in a total weight of 10% to 15% by weight of the composition;
said mixture of sulfonated methyl ester compounds and said zwitterionic surfactant are present in a combined ratio of 5 to 7.5:1 by weight;
Use of shampoo compositions. said mixture of sulfonated methyl ester compounds is a mixture between C14 sulfonated methyl ester and C16 sulfonated methyl ester, a mixture between C14 sulfonated methyl ester and C18 sulfonated methyl ester, or C16 sulfonated methyl ester and a C18 sulfonated methyl ester. Use of a shampoo composition according to claim 10 , wherein said mixture of sulfonated methyl ester compounds comprises 55% to 95% C16 sulfonated methyl ester and 5% to 45% C18 sulfonated methyl ester. Use of a shampoo composition according to any one of claims 10-12 , wherein said composition further comprises an inorganic electrolyte. 14. Use of a shampoo composition according to claim 13 , wherein said inorganic electrolyte is sodium chloride or potassium chloride. Use of a shampoo composition according to any one of claims 10-14 , wherein said zwitterionic surfactant is an alkylbetaine. 16. Use of a shampoo composition according to claim 15 , wherein said alkyl betaine is cocamidopropyl betaine. Use of a shampoo composition according to any one of claims 10-16 , wherein said cationic polymer is guar gum.
- Use of the composition. Use of a shampoo composition according to any one of claims 10-17 , wherein the oil phase is a silicone oil, mineral oil, vegetable oil, animal oil or an oil-in-water emulsion thereof.

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